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Updated: Jul 18, 2026

Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
Two-particle microrheology of quasi-2D viscous systems
V Prasad1, S A Koehler, Eric R Weeks
1Department of Physics, Emory University, Atlanta, Georgia 30322, USA.
Abstract:
We study the spatially correlated motions of colloidal particles in a quasi-2D system (human serum albumin protein molecules at an air-water interface) for different surface viscosities eta s. We observe a transition in the behavior of the correlated motion, from 2D interface dominated at high eta s to bulk fluid dependent at low eta s. The correlated motions can be scaled onto a master curve which captures the features of this transition. This master curve also characterizes the spatial dependence of the flow field of a viscous interface in response to a force. The scale factors used for the master curve allow for the calculation of the surface viscosity eta s that can be compared to one-particle measurements.
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